technomadia

I've just had a great conversation with Daniel Oliver, the plant manager and Oliver co-designer. He has a really good grasp on the potential voltage drop issues, and he was able to confirm for me the wire gauges that they are currently using. Inside the Oliver, the 12V jacks are all wired with 10 gauge wire. The small distribution panel (to the left as you come in the door) is wired even better - it is connected upstream with 4 gauge wire. This is fabulous, and is a sign of a well engineered design. The main charge wire from the battery forward towards the tow vehicle is 10 gauge, not the smaller 14 gauge I had been told. This is also good news. However, the final 4' cable that connects to the tow vehicle is using 14 gauge wire. This is a potential bottleneck, but one that is hard to avoid. Daniel has been looking for a cable manufacturer that does a cable like this with a thicker 10 AWG charge line, but he hasn't been able to find one. Most tow vehicles offer at best 10 gauge wire to the trailer charge line, so the Oliver's default wiring is probably at least as good as what you are towing with. Daniel and I discussed doing a test to see how well the Oliver's tow vehicle cabling does charging the battery. This will be easy to do accurately once we have an amp-hour meter hooked up to the battery, but for now - the following measurements should give a good idea of how significant the voltage drop issues may be. For each of these test cases, you should measure the voltage at the Oliver battery with the engine off, with the engine idling, and with the engine revving at a fast idle. Be sure to allow a few minutes to make sure that you get a stable reading. For comparison - you should also measure the voltage at the tow vehicle battery to see what the alternator is putting out. The difference will show you the voltage drop over the charge wire. Test #1 -- Fully Charged Oliver Battery / Fridge Off Test #2 -- Fully Charged Oliver Battery / Fridge On 12V DC Test #3 -- 50% Discharged Oliver Battery / Fridge Off Test #4 -- 50% Discharged Oliver Battery / Fridge On 12V DC To tell that the battery is at a 50% drained point - look for a resting voltage reading of 12.1V. If the voltage on the Oliver battery is 14.2V or up, the battery will be charging normally. If the voltage of the battery is at least 13.2V, the battery will be taking a trickle charge. If the battery voltage is below 12.73V, the battery is actually discharging and draining somewhat. This is what we really want to avoid. Current Oliver owners - post here if you have a chance to run these tests. I will respond here again when I get test results from Daniel in the factory. Experimentation always wins out over theory. *grin* - Chris

Go find yourself a Jeep Liberty Diesel. Great small SUV with the best towing fuel economy you will find. They only made them in 2005 and 2006, but they are worth hunting for. I love mine.

Googling around the net, I stumbled across this: http://www.freepatentsonline.com/D568793.html The design of the Oliver has been recently granted a US Patent: D568793 Congratulations to the inventors - James, Daniel, and Scott Oliver!

I've gotten another article posted, this one about RV electrical wiring issues: http://radven.livejournal.com/129172.html Of particular concern to Oliver owners is the gauge of the battery charge wire from the tow vehicle back to the Oliver's batteries. If you travel with the 3-way refrigerator using DC power, its current draw of 15-amps actually has the potential to leave your Oliver's battery dead-on-arrival, even though you are "theoretically" charging via your tow vehicle. This is a known problem in the Casita world, and it is solved by using a heftier gauge wire for the charge cable. I've heard that Oliver is using just 14 AWG wire, which is even worse than the 10 AWG that the latest Casita's use. Read on for more details.... ======= There are a few important things to know about electricity when wiring up an RV or solar electric system. 1) Electrical energy (Watts) is the product voltage (Volts) times current (Amps). This means that as you decrease the voltage on a wire, the current required to send the same amount of power increases. For example - to send 120 watts of power over a 120 volt electrical system (like typical home wiring) requires just 1 amp of current. But to send that same 120 watts of power over a 12 volt electrical system (like in your car or RV) requires 10 amps of current. 2) Electrical wires resist current flow. The higher the current (Amps) being pushed over the wire, the more the wire resists. The longer the wire is, the more the wire resists. And the thinner the wire is (the wire's gauge), the more the wire resists. Here, it is helpful to think of electricity like water. Say that it takes one minute to fill a gallon jug with a hose. Now say you wanted to fill up a bathtub (more Watts) in the same one minute. To do so, you can either vastly increase the water pressure (Voltage), or you can use a much bigger hose (same Voltage, but allowing for more current flow). When wires are resisting current, they actually waste energy by getting hot. And if you send too much current down too small of a wire, your wires can get so hot that they melt. This is generally considered to be a BAD thing, and this is why every circuit needs a circuit breaker or fuse to prevent too much current from overwhelming the wires, melting them, and starting a fire in the event of a short circuit. High Voltage & Small Wires or Low Voltage & Big Wires: What all of this means is that if you want to send more power over a wire, you generally have two choices - you can increase the voltage, or you can use a shorter and/or thicker wire. Thick wires are cumbersome and expensive - so if you can it is better to increase the voltage. This is one of the reasons why your household electrical system runs at 120V and not 12V - it is much more efficient this way, and even large appliances can be connected by affordable small gauge house wiring. Major regional power lines take this to an extreme - running hundreds of thousands of volts over long distances with wires the same thickness that you would use to hook up a large inverter to the 12V system in an RV. Unfortunately, in an RV we are pretty much limited to a low voltage 12V systems, though some large RV's and solar installations go with 24V or even 48V for vastly improved efficiency and to avoid the need for thick cables. But for a small trailer like the Oliver, 12V is the standard we have to work with, since batteries, tow vehicle charge voltage, mobile electrical appliances, and low voltage lights have been standardized on 12V since the dawn of the automobile. Without the option of running at a higher voltage, this means that adequate wire gauge becomes a critically important part of a safe and efficient electrical system. To see just how much power is lost running over various sized wires, I found a nice simple online wire voltage drop calculator here. Some examples of energy loss in 12V systems: 23.6% - 15 amps over 30ft of 14 AWG wire. 9.3% - 15 amps over 30ft of 10 AWG wire. 18.6% - 30 amps over 30ft of 10 AWG wire. 4.7% - 30 amps over 30ft of 4 AWG wire. Wire Gauge - Bigger equals Smaller: Non-intuitively, the larger the wire's gauge (AWG) number - the smaller the wire is. Typical 120V home wiring uses 12 or 14 gauge conductor, while the tiny wires within a telephone cable are typically AWG 24. Really thick wires are indicated by multiple zeros - AWG 0 (or written as 1/0), AWG 00 (2/0), and so on. AWG 0000 (4/0) wire is nearly half an inch across - and it is expensive, stiff, and very hard to work with. Most RV loads are relatively low power and despite the low voltage, they can operate just fine and without too much efficiency loss with 12 AWG or 14 AWG wire. A typical RV incandescent light burns 12W, and thus only 1 amp of of current is required. The Oliver's standard 25W halogen bulbs only require 2 amps. And the LED equivalent lighting to a 25W halogen uses just 3.3W, a barely perceptible 0.25 amps. There are however a few places in an RV where the currents can get high, and where wire gauge really starts to matter: Aux 12V Outlets: People tend to use 12V auxiliary outlets for either low power gadgets (like cell phone chargers) or high powered appliances (like small inverters, blenders, or even coffee pots - which can use 17 amps!). Yet many RV's come pre-wired with inadequate wiring to these jacks, using the same gauge wire that would be suitable to power a single 12W lightbulb. This was certainly the case in my Tab clamshell, where the 12V aux jack in the kitchen proved to be a horribly inefficient power source for even a small inverter. If a 12V jack is inadequately wired, a significant amount of your battery power will be going towards heating up wires and not powering your inverter or appliance. Many higher powered loads may fail to work at all. This is why it is always better to connect even a small inverter directly to your RV battery, if possible. I've heard that the Oliver uses 10 gauge wiring for all the aux 12V outlets, which is a reasonable amount for this job. Refrigerator: The 3-way refrigerator in most RV's like the Oliver can run off of 12V DC, 120V AC, or propane. While running off of DC, the Oliver's refrigerator requires a massive 15 amps of current (contrast that with the less than 2 amps required with 120V AC). To handle a 15 amp load, the refrigerator specifies 10 AWG DC wiring and maximum wire length of 20 feet. This heavy current draw is why you should never leave a 3-way refrigerator running on DC power while stopped. The fridge can drain your trailer battery in just a matter of a few hours - and if your tow vehicle lacks a battery isolator circuit you could find that battery dead as well after a long lunch! Tow Vehicle Charge Line: When you are towing, the battery charge line from your tow vehicle provides charging current to your trailer to top off the batteries while underway. This wire though has a long distance to cover - from your engine's alternator way up front to your trailers batteries, which in the Oliver are located in the back corner. If your trailer battery is at all run down and needing charging, or you are running the refrigerator on DC power - this line also needs to carry a lot of current. The current demands are even higher if you have BOTH a low battery and the fridge set to run on DC. Unfortunately, most trailers use undersized wiring for the tow vehicle charge lines - and you can actually easily end up with a situation where your battery discharges and drains while driving instead of charges. This has been a well discussed design flaw in the Casita world - you can read posts on the subject here, here, here, and particularly here. To get around this problem, some Casita owners have even resorted to using an inverter in their tow vehicle and running a shore power extension cord back to their trailer. (High voltage 120V AC power is so much more efficient over distance that this crazy sounding scheme actually makes electrical sense!) I have been told that the Oliver presently uses 14 gauge wire for the charge line, which is inadequate for the job. Based upon the experiences of many Casita owners, AWG 4 or AWG 8 wire would be better, or at the very least AWG 10. I am hoping that Oliver will switch to a higher gauge wiring for the tow vehicle charging hookup. But even if Oliver does upgrade the charging wire in the trailer, most tow vehicles have AWG 10 or smaller wires running from the trailer hitch to the engine. For optimal charging while on the go, this charge line should be upgraded as well. Warning: Until you know for certain how your own particular charging system performs, you should not count on getting a good full charge of your trailer battery from your tow vehicle. And if you are running your refrigerator on 12V power while underway, you may actually arrive with your batteries dead or lower than you started. Be on guard! Inverter Wiring: A 1000W or 2000W inverter needs to be able to handle momentary power surges of twice the maximum load, which means there is the potential for a huge amp draw from the battery. Because of this, any large inverter is going to require some LARGE cables, and you will want to place the inverter as close to the battery bank as physically possible. Some examples - a basic Xantrex 1500W inverter recommends AWG 0 (1/0) cable when placing an inverter within 6 feet of the batteries, and 00 (2/0) AWG wire for six to ten feet distance. The Xantrex Prosine 2.0 2000W inverter / 100A charger suggests 4/0 AWG wire, and that the inverter be located no more than 12 feet from the batteries. Charger / Converter: If you are not using a combination inverter / charger, you will still want a reasonably sizable wire between your converter and the batteries. Most RV chargers are capable of putting out 30 - 90 amps of charge current. The stock power converter in the Oliver is the Progressive Dynamics PD9145A, which can put out 45 amps of current. Based on how close the converter is located to the Oliver's batteries - AWG 8 or AWG 10 wire should suffice. Ground Wire: Finally - it is important that the grounding wire from the battery to the frame be able to handle ALL of the current that the power system will put out. If you install a large inverter into an RV that has inadequate grounding, you are at risk of overwhelming the ground wire when the inverter handles the surge of large loads starting up. You should make certain that your ground wire is at least as as thick as the largest wires hooked up to the battery. Solar Considerations: If you are using solar panels and you have invested in an MPPT controller and efficient AGM batteries, it would be a shame to build a system that throws that efficiency away by using small and less efficient wires. 14 gauge wires may "work" just fine, but if a significant percentage of the energy you are collecting from the sun is wasted before it every gets to your battery, you are certainly missing the point. When running with 20 amps of input, the BlueSky 2512iX MPPT solar charge controller recommends a maximum wire distance of just 10.2 feet of AWG 10 wire between the solar panels and the batteries (passing through the charge controller), or only 16.2 feet with AWG 8 wire. One of the advantages of an MPPT controller however is that the wires between the solar panel and the charge controller can run at a higher voltage (and thus with lower current), reducing the amount of power lost by wire resistance. The MorningStar SunSaver MPPT controller can even handle a 75 V input! For the 200W solar system with 21.5V panels that I am constructing - AWG 10 wire should suffice. Concluding Thoughts: I've heard (and am waiting to confirm) that the Oliver uses AWG 10 wire for all the DC wiring internally, which is great - and way better than most RV's. But I've also heard that the wiring to the trailer hitch is AWG 14, and this is inadequate for both the charge and ground lines. I am hoping that the factory will change this standard, or else Oliver owners face the same mysterious "dead on arrival" batteries that plague some Casita owners who run their refrigerator on 12V while in transit.

Oh my.. what did I start here? *giggle* Based on the responses here, I think Chris and I have indeed found not only the right trailer for us, but the right community too! Ok.. so, next Oliver Rally will need to have Stripper Pole lessons/demos. ~Cherie~

The real interesting question... What would you use for a tow vehicle on Mars??? *grin*

I wonder what it would take to upgrade the Oliver to handle Martian conditions... The double paned windows are a good start. We'd probably want an airlock too...

I believe that the pole is used as a support system to support the back cushion when the small dinette is in table mode, and as a bit of separation between the small dinette and bed area. I like it much better than the Casita's way of handling this with a divider wall - the pole creates a much more open looking space. Although, I have fun telling people we'll be having a stripper pole in our trailer when they ask about it. *giggle* - Cherie

One thing that has always concerned me with living in a such an easily mobile home is the fear that someday I'll find our house literally hauled away stolen. Even with a hitch lock, as long as the wheels can roll, this is an all too real possibility. With my Tab I've taken to often locking our bikes to the tongue with a U-Lock to make rolling more complicated, and sometimes I also route a chain through the wheels. I had an idea today for a small change to the Oliver that would make it MUCH more difficult for a thief to make off with the trailer, even if they had a flatbed truck. This technique takes advantage of the electric leveling jacks. Imagine if the Oliver had a switch inside (maybe even hidden, and certainly unlabeled) to cut power to the leveler jacks. This simple addition would make it impossible for anyone outside the trailer to raise the jacks for towing. The back jacks do not even have any sort of externally accessible manual override crank. I think this would prove to be a wonderful security addition to the Oliver. Any thoughts on this? What do the rest of you do to secure your trailers from theft? Cheers! - Chris

We found a great mobile desk on e-bay last year. It lets the passenger / navigator work away comfortably all day. We've even done video conferences while in motion. *grin* - Chris

Thanks for your battery postings! Do you think you will go to 6v ? Mountainborn has a VERY nice gen cover for his Yamaha 3000 which could be easily downsized to my Honda 2000. I have seen it and it is one of the nicest I've seen on ANY small trailer. FYI, by turning the electric tongue lift to one side (curb best IMHO) you can pick up almost an 1.5" of tongue room for your box! And believe me, every little bit counts!! Great tip on turning the electric lift to the side - I just wrote to Robert about that. Where can I get more info on the generator cover? We are probably going to get a Honda 2000, but I haven't figured out how to secure and protect it yet. As for 6V - yes, I think so. My current leaning is two big LifeLine AGM's for 220 total amp hours of storage. Cheers! - Chris

Cherie, you can't use your haircurler when Air Conditioning ON!!!!! What's a haircurler? ~Cherie~ The naturally curly redhead

I've been writing articles and blogging all the research I have been doing into our custom Oliver design. They are posted here: http://radven.livejournal.com/tag/oliver So far, I've written several in depth articles about designing a solar power system and selecting the best components. Enjoy! - Chris

Chris, I just want to tell you how much I appreciate your posts! I have learned more, since you have joined our forum, than I ever thought I would be interested in knowing! You make learning about this technical stuff interesting and fun! Usually when I start reading anything technical, I develop brain freeze and then the brain teflon kicks in and nothings sticks! I just wanted you to know this old lady appreciates you! Actually, I imagine everyone who reads your posts is just as appreciative as I am! Geri *blush* But... I do actually have a knack for this stuff. Around 10 years ago I used to be the Technical Editor for a computer magazine. It is still around on newstands - now known as "Maximum PC". I'm glad you are enjoying the posts! - Chris

A Honda EU2000 converted to work on propane sounds like a perfect match for the Oliver, particularly since it will save us needing to carry a gas canister around. How quickly does the EU2000 burn through propane? Where did you get your propane conversion kit? Have you had any issues with your setup? Thanks!

That is a nifty veggie oil conversion - thanks for the link. We run biodiesel when we can find it, but the cost and complexity of going for pure veggie oil has held us back. Still - it is fun to find a B100 station and to drive around with french-fry exhaust for a while.

I'm curious... Has anyone actually weighed their Oliver?? Robert told me that they do not weigh each individual unit as it leaves the factory, which I thought was standard for most RV makers. It would be nice to know what a fully equipped Oliver in the real world ends up weighing. - Chris // http://www.technomadia.com

Yet another bit of distilled research, as posted here: http://radven.livejournal.com/128906.html === Boondocking or "dry camping" in an RV without a battery monitor is like driving a car without a gas gauge. If you fill your tank up everyday and never drive further than to the corner store, this strategy can work just fine. But if you are going to do any sort of serious camping without electrical hookups or a daily dose of generator, it is essential that you keep a close eye on your batteries. This is particularly important when relying on solar, because you will rarely know for sure what state of charge the sun has left you with. Batteries will last longest if you never cycle them below 50% capacity, and going over 80% drained starts to seriously damage even the best "deep cycle" batteries. If you use the "lights are getting dimmer" method to tell that your batteries are running down, they will almost certainly be permanently dead within a year. Not good - particularly if you've invested in expensive AGM batteries. Voltage Metering: The simplest way to keep an eye on your batteries is via a voltage meter. A fully charged 12V battery will read 12.73 V, at 50% capacity 12.10 V, and when you have just 20% left (critical territory!) 11.66 V. The Oliver trailer includes a system status panel that will show you your battery voltage, and by keeping watch you can get a sense for how you are doing. But there is a BIG catch. To get an accurate and meaningful voltage reading, your batteries must have been sitting idle for at least six hours, and preferably twenty four. That means no lights on, no charger connected, no solar running - essentially no use whatsoever. If the battery is not well rested, particularly if it is currently being used (even if just to power a light), the voltage reading is going to be off - and therefore nearly useless. Imagine if your car's gas gauge was only accurate after you had been pulled off the highway for six hours. That is not particularly conducive to getting anywhere.... Consider the voltage meter to be essentially just a "guess gauge", and not a gas gauge. Specific Gravity Testing: You can also very accurately test the state of charge of well rested flooded lead acid batteries by using a hydrometer to measure the specific gravity of each individual battery cell. But doing this involves sucking up battery acid into a glass tube. Not fun, or typically practical. In a car, this would be akin to pulling off the road, letting your engine cool, and then sticking a hose into your gas tank to see how much fuel remains. You really don't want to be doing this. Trust me. Battery Monitors: A real battery monitor works by measuring the current flowing into and out of your battery via a very accurate shunt. Once the monitor detects that your battery is full, it keeps track of every amp of outflow, and it gives you a percentage remaining readout or an easy to read empty to full bar graph. This at last gives you a usable "gas gauge" view of the sate of your batteries. Battery monitors are not cheap, but they are worth it. If you are actually going to be using your batteries for more than a day or two of disconnected camping, I consider a proper battery monitor to be essential equipment. There are only a few options on the market however: + TriMetric TM-2020: The TriMetric has been on the market forever, and it is a trusted and well proven design. It is also the most affordable battery monitor around, available for about $165. The TriMetric has a simple (though unattractive) LED display that shows you the battery % full readout, and which can also display battery voltage and current. The maker of the TriMetric also has available the much more expensive PentaMetric unit which does data logging and which can be interfaced with a PC. The PentaMetric is overkill for all but the most extreme RV installations. + BlueSky IPN-Pro Remote: The IPN-Pro remote requires and works in conjunction with a BlueSky solar charge controller (like the 2512iX). The IPN-Pro provides a very attractive display that combines both solar charging status with real battery monitoring. It even learns your batteries internal charge efficiency, becoming more accurate over time. If you have a BlueSky solar controller - this $180 option is an ideal match. + Magnum Energy Battery Monitor: If you have one of the higher end Magnum Energy inverters (expensive), and the Magnum Energy inverter remote control interface (also expensive), you can add real battery monitoring to your system via this $160 upgrade. I was disappointed however to discover that this battery monitor will not function when combined with the more affordable Magnum MM series inverters. + OutBack Power Systems: If you are looking to spend a LOT of money and you have a much larger RV than the Oliver, OutBack Power Systems produces a line of high-end inverter / chargers and solar controllers that can be combined with their FLEXnet DC battery monitor and MATE remote display to produce a very snazzy looking integrated system. + Xantrex Link 10: The Link 10 is a basic battery monitor with a simple LED display and red, yellow, and green status lights to indicate how close to critical you are. The Link 10 does not display a percentage battery remaining view, but it will tell you how much run time you have left at your current load. Aprox $200. + Xantrex Battery Monitor: This $230 monitor is very similar in functionality to the Link 10, but it does offer a nicer display, a proper battery percentage readout, and an option for data logging to a PC. + Xantrex LinkLITE: The Xantrex Battery Monitor is currently being discontinued and replaced with the new LinkLITE and LinkPRO models, which are due to ship in August. The LinkLITE will cost $270, can monitor two battery banks, trigger a generator to start when the battery is getting low, and it looks to have a very clear and intuitive display readout. Current Awareness: One of the nice side effects of using a real current measuring battery monitor is that it shows you exactly how much power you are using at any given time. When you flip on a light switch, power up an inverter, or turn on the radio, you will see exactly how much additional current that new load is drawing. Without this sort of awareness, you may never even realize which things are the major drains on your battery. Once you have a battery monitor installed, it is a good idea to work your way through your RV - turning each light and gadget on and then off, one at a time. Make a note of the current draw of every item. This information will be invaluable later, particularly if you are trying to be miserly and maximize your run time on batteries. Concluding Thoughts: If you are using cheap Walmart special batteries, it is actually not unreasonable to abuse them till they drop, and to just plan on replacing them every year. If this is the case, a real battery monitor is probably overkill for you. Pay attention to the battery voltage, never ever run things till the lights get dim, and you'll be fine for a while. But if you are going to be doing a lot of off grid camping, or you are planning to spend a lot of money on expensive batteries, you are a fool if you do not also invest in an accurate way to track their condition. You really should get a battery monitor of some sort. If you have a BlueSky solar controller, the best choice is obviously the IPN-Pro. If you are building a Magnum or Outback complete system, you also have an obvious choice - though certainly both of these are overkill for something as small as an Oliver. If you are getting a standalone battery monitor, I'd base my choice primarily on aesthetics - since you do NOT want your battery monitor mounted in an out of the way place. You do want your gas gauge to be readily seen, after all.

Yep - an evaporative "swamp cooler" is the only power efficient way to keep cool on battery power. Sadly, the efficiency drops rapidly in humid environments. But in the desert, this sort of AC can work great. Our little hand-held Misty Mate works on the same principle, on a much smaller scale.

Most people tend not to keep the tow vehicle hitched up and plugged in while camping. Besides - I have a luggage rack and my ultralight landing gear already stuck up on the roof of my tow vehicle... *grin*

As posted in my Oliver blog thread: http://radven.livejournal.com/tag/oliver Direct Link: http://radven.livejournal.com/128310.html (Read the version linked above to be able to click on the links to more details...) ====== Solar panels are only half the battle... You next need something to take the sun juice and squeeze it into your batteries. There are plenty of reasonably priced basic solar charge controllers, and if you have small panels or you are not overly concerned about every last drop of efficiency - a basic charge controllers is a wise choice. Something like the MorningStar SunSaver SS-10 costs around $50, and can handle 10 amps of power, enough for 140W of solar panels. More advanced solar charge controllers support "Maximum Power Point Tracking", or MPPT. MPPT works by performing a DC-to-DC conversion, allowing the solar panel to run at a higher voltage than the battery. This conversion boosts the charge current into your battery, and can improve overall efficiency by as much as 30%. MPPT is most effective when your battery voltage is low and the solar panels are cold, a common scenario in an RV every morning after a chilly night running lights, heaters, fans, and laptops. MPPT controllers designed for small systems are still relatively rare, and a bit expensive. But the extra efficiency is worth it to me. Here are the contender MPPT solar charge controllers I am looking at: (links go through to the lowest prices I have found...) + MorningStar SunSaver MPPT: 15 amps. Max input voltage: 75V. Suitable for around 200W of solar. Temperature compensation cable optional ($22). Can handle high panel voltages. The MorningStar is a brand new design (just shipped), and it is getting rave reviews from solar geeks. $190 + Heliotrope HPV-22B: 22 amps. Max input voltage: 30V. Suitable for around 300W of solar. Temperature compensation cable included. "Shore Power Mode" for RV's. Based upon the older BlueSky SB2000E design. $265 + BlueSky 2512i: 25 amps. Max input voltage: 35V. Suitable for around 350W of solar. NO temperature compensation supported. $167 + BlueSky 2512iX: 25 amps. Max input voltage: 35V. Suitable for around 350W of solar. Optional temperature compensation cable ($29). Also adds support for battery equalization and control of an auxiliary load - such as dusk to dawn lighting. $201 + BlueSky Solar Bost 3024: 30 amps. Max input voltage: 57V. Suitable for around 400W of solar. Optional temperature compensation cable ($29). Also adds support for battery equalization and control of an auxiliary load - such as dusk to dawn lighting. $287 Temperature Compensation: If you are going to invest in expensive AGM batteries, it is wise to make sure that your solar charge controller has a battery temperature sensor installed to adjust the charge voltage based upon the actual battery temperature. Otherwise, you risk damaging your batteries by over or under charging. Voltage Headroom: Typically, to interface with 12V batteries, you want solar panels with around 17V peak charging voltage. To use panels with a higher charging voltage, you need a MPPT charge controller with enough voltage input range to down-convert the panel voltage. In this case, the higher panel voltage actually becomes an advantage, since there is less line loss running a higher voltage over the wire. The BlueSky 3024 and particularly the MorningStar SunSaver support using higher voltage input. This will let you make use of several larger solar panel options that will overwhelm the other controllers, or you have the flexibility to string multiple smaller panels together in series. The key is to have the open circuit voltage of the panels LOWER than the max input voltage for the charge controller. The MorningStar controller really excels here. Mounting Location: All of these charge controllers are relatively small and can be tucked into any out of the way bulkhead, other than the Heliotrope HPV-22B which needs to be mounted onto an exposed wall area. The HPV-22B has a status screen that shows you battery voltage, and charge current in from the panels and out to the batteries. The HPV-22B also has a "shore power" mode switch which allows you to force the solar charger to step back while you are plugged in. This sort of system status information is nice to have. To get this with the BlueSky controllers, you need to add the optional IPN-Pro Remote ($180). The IPN-Pro does much more than just show charge controller status though. It also acts as a battery monitor, and gives you a real "gas gauge" readout of battery status, an extremely valuable feature. The MorningStar controller can interface with a PC, and there is also a basic remote status display available. Multiple Panel Considerations: Having a larger charge controller (like the BlueSky 3024i) gives more headroom for future expansion, but it is actually often better just to add a second charge controller later - particularly if you will be using mismatched panels. The huge 75V input range on the MorningStar also makes adding multiple panels in series easy. Concluding Thoughts: Each one of these options has merits. But right now I am leaning towards the same setup that is in my current Tab. The BlueSky 2512iX will prevent me from using high voltage panels, but that is really the only limitation. I know and love the ease and attractiveness of the IPN-Pro interface and battery monitoring capabilities. For anyone else installing a system - the BlueSky hardware is a great foundation to build on. You can start relatively cheap, and add the IPN-Pro later. I also have been VERY impressed with the quality of the BlueSky data sheets and documentation. The HPN-22B loses points there for not even having the manuel or detailed specs posted online.

I've just posted all my research into solar panel options here: http://radven.livejournal.com/128003.html Here is the content of that post. Click through to the original to follow links... ==== One of the biggest challenges to living a solar powered technomadic life in a trailer as small as the Oliver is the lack of roof space to mount solar panels. The Oliver's fiberglass roof isn't just small, it is not even flat. It rises up in the middle to allow for interior headroom, and it is lower on the sides. By removing the satellite TV antenna, and by having the factory slide the roof fan back towards the air conditioner, and the bathroom fan forward a bit - the flat area left for potential solar goodness is around 61" x 28", give or take a bit. (Without relocating the vents, there is around 34" length...) I've been researching a few potential panels that may potentially prove workable: + Kyocera KC-65T: 65W, 17.4 V peak, 29.6" x 25.7" x 2.1" x 13.2 lbs -- $350 ($5.38/watt) + Kyocera KC85TS: 85W, 17.4 V peak, 39.6" x 25.7" x 24 lbs -- $438 ($5.15/watt) + AM Solar AM100: 100W, 21.5 V peak, 57.25" x 21.25" x 1.92" x 20.8 lbs -- $550 ($5.50/watt) + Kyocera KD135GX-LP: 135W, 17.7 V peak, 59.1" x 26.3" x 1.4" x 28.7 lbs -- $655 ($5.04/watt) + Mitsubishi PV-MF170EB3: 170W, 24.6 V peak, 62.2" x 31.5" x 1.8" x 32.2 lbs -- $761 ($4.48/watt) + Sharp NT-180U1: 180W, 36.86 V peak, 62" x 32.5" x 1.8" x 37.5 lbs -- $905 ($5.03/watt) Technical Note: Typically, to interface with 12V batteries, you want solar panels with around 17V peak charging voltage. To use panels with a higher charging voltage, you need a MPPT charge controller to down-convert the panel voltage. I included these higher voltage panels because I am leaning towards an MPPT capable charge controller. Mounting Hardware: The next challenge is the mounting hardware. Flat mounts are simpler, but tilting mounts give you the option of pointing the panels towards the sun while parked, which can give you a substantial boost in power. But they also then require you to figure out a way to get up on the roof to do the tilting.... Northern Arizona Wind & Sun has a page full of various RV mounts to consider. The AM Solar folks have a nice set of RV-optimized mounts with tilt bars. These mounts seem particularly well suited for roofs that are not perfectly flat. Multiple Panel Options: The AM Solar folks have been talking with the Oliver plant manager, and they think they have come up with a way to join two AM100 panels together sharing a single set of tilting mounts. This will result in 42.5" of width, with around 5" of wing-like overhang to either side of the Oliver's hump. Hmmm.... The other option for multiple panels would involve having a second deployable panel that we only set up while parked for extended periods. The second panel could be set up freestanding at the end of a long wire so that it could be put in the sun while we are parked in the shade, or perhaps it could be mounted as a shade over the rear window like this ingenious Casita modification. With either of these options storage and setup becomes a chore, but the extra capacity for living off-grid may prove worth it. Concluding Thoughts: The Kyocera 65W panel looks like it will fit in the area where the satellite dish sits on current Olivers, without the need for relocated vents in the roof. This is probably the best option for current Oliver owners looking to upgrade to solar. Starting from scratch, I am torn between the 2x AM Solar option, or trying to squeeze a single larger panel on like the 180W Sharp. The 135W Kyocera is probably the largest panel that will fit on the roof without any overhang.

Air conditioning is WAY too power intensive to be practical off of batteries. Even with a huge battery bank, by the time the trailer started to cool down the batteries would be dead. You really need a generator or shore power for air conditioning. Or... You can use a small water mister, and spray into the airflow from the ceiling fan. We used a "Misty Mate" that would run for 15m or so per fillup with water. In dry climates, the water instantly evaporates and can dramatically cool things down. Good luck staying cool, - Chris // http://www.technomadia.com

Here is my current rough outline of upgrades (and downgrades) I will be asking to have done to our Oliver... Downgrades: Satellite Television Antenna: I need to clear up roof space for the solar system, and I really could care less about television. That's what Netflix is for... Entertainment System: The stock system has a 15" screen - no better than our laptops. And the DVD player only outputs low-res composite video to the screen. I want much better. (Maybe) Microwave / Convection Oven: Most Oliver and Casita owner's who have an integrated microwave seem to never user it and they wish that they had the extra cabinet space instead. We could if desired instead carry around a small toaster oven or cheap microwave - and we could then use it for outdoor cooking as well. Cherie and I are still on the fence about whether or not we want to ask them to leave this off... Upgrades: Double Pane Windows: Extra insolation is always a good thing. Enhanced Batteries: I am going to research the largest possible battery capacity that can be squeezed into the Oliver's battery box. Right now I am debating between Lifeline AGM's or Trojan flooded lead acid. Combination Charger / Inverter: The stock battery charger / 12V converter will be replaced with a combination inverter / smart charger / transfer switch. This way the entire trailer will have functional AC power even when disconnected from shore power, and the battery will be able to charge quicker when I do resort to using the generator. I am researching several alternatives for this component, debating the tradeoffs of cost, modified sine-wave or true sine wave power, and charger and inverter capacity. Solar Panel(s) & Charge Controller: The Oliver's roof is oddly shaped, and it will be hard to fit more than one panel up there without engineering some sort of deployable slide out or trifold system to allow multiple panels to stack for transport. But I have found a few promising panels - and at the very least I should be able to get a single 130W panel on the roof. I'm also researching the ideal charge controller to interface the panel to the batteries. The MorningStar SunSaver MPPT is currently the top choice. Battery Monitor: The Oliver comes with an integrated voltage gauge for monitoring the battery, but this is all but useless for getting an accurate sense of how much battery capacity actually remains. I will instead have a proper amp-hour meter installed to track battery performance. Cell Phone Booster: A roof mounted antenna combined with a signal amplifier and interior rebroadcast antenna will give us vastly better cellular voice coverage, and faster Internet speeds as well. Enhanced AV System: I have been very disappointed researching the systems designed for "mobile" and RV use. Instead, I am contemplating a "home theater in a box" system from Sony or Panasonic. This way I can get vastly better audio and video quality in a cheaper system that takes up essentially the same amount of space and which hardly burns up any more power. 22" Widescreen Monitor: Instead of the small square factory 15" TV, we will have them mount a 21" or 22" widescreen monitor on the wall that will also take HDMI input from the AV system. This will give us a stunning screen for movie watching, and the swing arm will also allow us to position it over the table for use as a second monitor with one of our laptops. The swing arm should also be able to position the monitor so that it is viewable out the side window from the front porch for outdoor movie nights. Tongue Generator Mount: We plan to get a small Honda or Yamaha generator for running the AC and topping off the batteries when needed. We'll want a way to secure the generator to the trailer tongue. And of course, we will also be picking out custom fabrics, panel colors, and even tiles for the interior. I think this covers the most of the upgrades that we will be building into our Oliver. I expect that I will be posting in depth articles here detailing my research into each of them. Any thoughts, suggestions, or comments??? - Chris // http://www.technomadia.com

What range away from your trailer is the cell phone boost effective? Does it work in your tow vehicle, so that you benefit from the increased signal while driving?